Method and device for controlling at least one deceleration device and/or an output-determining actuating element of a vehicle drive device

ABSTRACT

A device and a method for triggering at least one deceleration device and/or one output-determining actuator element of a vehicle propulsion system, in particular for automatic longitudinal vehicle regulation, a first surroundings sensing device being provided, which delivers longitudinal value-optimized measured values, a second surroundings sensing device being provided, which delivers object lateral dimension-optimized measuring values, and an analyzer device being provided, which receives the output signals of the first and second surroundings sensing devices and the measured values of the first and second surroundings sensing devices being used for object identification. The device and the method are furthermore suitable for initiating or performing vehicle deceleration for collision avoidance or for alleviating the severity of a collision.

FIELD OF THE INVENTION

The present invention relates to a device and a method for triggering atleast one deceleration device and/or one output-determining actuatorelement of a vehicle propulsion system, in particular for automaticlongitudinal vehicle regulation, a first surroundings sensing devicebeing provided, which delivers longitudinal value-optimized measuredvalues, a second surroundings sensing device being provided, whichdelivers object lateral extension-optimized measured values, and ananalyzer device being provided, which receives the output signals of thefirst and second surroundings sensing devices and the measured values ofthe first and second surroundings sensing devices being used for objectidentification. The device and the method are furthermore suitable forinitiating or performing vehicle deceleration for collision preventionor for alleviating the severity of a collision.

BACKGROUND INFORMATION

The publication “A Small, Light Radar Sensor and Control Unit forAdaptive Cruise Control” by Olbrich, Beez, Lucas, Mayer and Winter,SAE-Paper 980607, presented at the SAE International Congress andExposition, Detroit, 23, Feb. 23-26, 1998, describes a motor vehicleradar sensor, which detects objects in the travel path of a vehicle andcontrols the vehicle deceleration devices or vehicle accelerationdevices as a function of the detected objects. If the radar sensordetects no object or only detects objects which are not identified asvehicles traveling ahead, the vehicle velocity is regulated as constantvelocity regulation. However, if the radar sensor detects objects whichare identifiable as vehicles traveling ahead, the vehicle velocity isregulated as constant distance regulation. For this purpose, athree-beam microwave transceiver is used, which emits afrequency-modulated continuous-wave signal and receives reflectedpartial waves.

German Patent Application No. DE 100 11 263 A1 describes an objectdetection system, which is provided for vehicles in particular, in whichthe object detection system has a plurality of object detectors and/oroperating modes for different detection ranges and/or detection areas. Aradar sensor which has a relatively great detection range and arelatively small angular detection area in a first operating mode and acomparatively small detection range and increased angular detection areain a second operating mode is preferably used as the object detector.This system uses different surroundings sensing devices, eachsurroundings sensing system covering a different detection area.

In the book “Handbook of Computer Vision and Applications,” AcademicPress, Boston, 2000 by Jähne, Hauβecker and Geiβler, in the section“Motion” on pages 307 through 392, methods for processing moving imagesare described, in particular methods for determining and processing the“optical flow.”

SUMMARY OF THE INVENTION

A core of the present invention is to provide a device and a method fortriggering deceleration devices or output-determining actuator elementsof vehicle propulsion systems in particular as automatic longitudinalvehicle regulation, the vehicle's surroundings being detected bysurroundings sensing devices in such a way that the surroundings sensingdevices complement one another, forming a redundant overall system.

The system according to the present invention advantageously providesfor the measured values of the second surroundings sensing device to beused for verification and/or provision of additional information inanalyzing the measured values of the first surroundings sensing device.This makes it possible to verify the measured values of the objectsdetected by the first surroundings sensing device via the measuredvalues provided by the second surroundings sensing device, andadditional information, such as the lateral object dimension, mayoptionally be assigned to the objects detected by the first surroundingssensing device. It is also possible to verify the measured values of theobjects detected by the second surroundings sensing device via themeasured values provided by the first surroundings sensing device, andadditional information, such as the exact object distance or the azimuthangle of the object, may optionally be assigned to the objectsrecognized by the second surroundings sensing device.

It is furthermore advantageous that the measured values of the firstsurroundings sensing device are used for verification and/or forprovision of additional information in analyzing the measured values ofthe second surroundings sensing device. This makes it possible to verifythe measured values of the objects detected by the second surroundingssensing device via the measured values provided by the firstsurroundings sensing device and additional information, such as theexact object distance, may optionally be assigned to the objectsdetected by the second surroundings sensing device.

The measured values of the first surroundings sensing device may beadvantageously used for reducing the complexity of the signal processingin the second surroundings sensing device, in particular for limitingthe analysis of certain regions of the detection area of the secondsurroundings sensing device.

The system advantageously provides for automatic vehicle deceleration tobe triggered and/or performed for longitudinal vehicle regulation toavoid a collision and/or to alleviate the severity of a collision.Automatic vehicle deceleration is triggered or performed as a functionof the objects detected by the surroundings sensing devices in thedetection area of the surroundings sensing devices.

It is furthermore advantageous that the first surroundings sensingdevice is a radar transceiver device. Radar transceiver devices offerthe advantage that their operability is independent of weatherconditions, and that they permit distances and relative velocities ofthe recognized objects to be determined very accurately.

It is furthermore advantageous that the first surroundings sensingdevice is a radar transceiver device. Lidar systems emit coherent,monochromatic light and receive the reflected partial waves. Lidarsystems make it possible to determine the distance and relative velocityof detected objects very accurately. If the lidar system is designed asa scanning lidar system, it is also possible to determine the lateraldimension of the object.

The second surroundings sensing device is advantageously designed as animage detection system. This image detection system may beadvantageously designed as a monocular video camera or as a stereo videocamera. Providing a monocular video camera makes the cost-effectiveimplementation of the device according to the present inventionpossible. Providing a stereo video camera makes reliable,three-dimensional analysis of the recorded stereo image pairs possible.

The implementation of the method according to the present invention inthe form of a control element which is provided for a control unit of anadaptive cruise control system of a motor vehicle is of particularimportance. A program which is suitable for being run on a computer, ona microprocessor in particular, and for carrying out the methodaccording to the present invention is stored in the control element.

Therefore, in this case, the present invention is implemented by aprogram stored in a control element, so that this control elementprovided with the program represents the present invention, as does themethod which the program is suitable for carrying out. In particular,electrical memory media, a read-only memory for example, may be used asa control element.

BRIEF DESCRIPTION OF THE DRAWING

The FIGURE shows a schematic representation of the device according tothe present invention.

DETAILED DESCRIPTION

The FIGURE shows a processing device 1 which receives input signals.These input signals are supplied to processing device 1 via an inputcircuit 2 and further processed. The input signals originate from afirst surroundings sensing device 3, a second surroundings sensingdevice 4, and further, optionally providable input variable devices 5.These optional input variable devices 5 may include driver-actuatableoperating elements for controlling processing device 1, for example, inthe form of switches, buttons, a gas pedal switch, or gas pedalpotentiometer, or a brake pedal switch or brake pedal potentiometer;input variable devices 5 may also be sensors, for example, velocitysensors or acceleration sensors which relay the measured variables toprocessing device 1. First surroundings sensing device 3 is asurroundings sensing device which provides longitudinal value-optimizedmeasured values. Longitudinal value-optimized measured values areunderstood as measured values originating from a surroundings sensingdevice, capable of determining distances or relative velocities todetected objects very accurately, but are ill-suited or unsuitable fordetermining the lateral dimensions of objects. A surroundings sensingdevice which provides longitudinal value-optimized measured values isunderstood as a radar transceiver, for example, capable of veryaccurately determining distances between the transmitter and thereceiver, i.e., the distance in the direction of propagation of thewaves. In addition to, or instead of, this radar system, a lidartransceiver may also be provided, which also delivers longitudinalvalue-optimized measured values.

Furthermore, a second surroundings sensing device 4 transmits measuredvalues to processing device 1. According to the present invention, thissecond surroundings sensing device 4 is a device which provides objectlateral extension-optimized measured values. A surroundings sensingdevice providing object lateral extension-optimized measured values isunderstood as a device capable of accurately determining the dimensionof the detected objects perpendicular to the direction of propagation ofthe measuring waves used. The use of an image detection system, designedeither as a monocular video camera or as a stereo video camera, isprovided as second surroundings sensing device 4 which provides objectlateral extension-optimized measured values. Such image detectionsystems are capable of determining the dimensions of the detectedobjects perpendicular to the direction of propagation of the measuringwaves; however, these systems have the disadvantage of determiningdistances in the direction of propagation of the measuring waves veryinaccurately or not at all.

These input variables which are supplied to processing device 1 viainput circuit 2 are supplied to a computing device 7 via a data exchangedevice 6, which may be designed as a bus system, for example. Themeasured values provided by first and second surroundings sensingdevices 3, 4 are analyzed in computing device 7. For this purpose, theobjects detected by first surroundings sensing device 3 are superimposedon those detected by second surroundings sensing device 4 and thus theobjects detected by both surroundings sensing devices 3, 4, areaccurately detected with respect to distance, relative velocity andlateral dimension. As a result of such a combination of the objectmeasurement results detected by both longitudinal value-optimized andobject lateral dimension-optimized surroundings sensing devices 3, 4,accurate measured values are obtained and redundancy regarding objectswhich are highly relevant with respect to the driving safety of theautomatic longitudinal vehicle regulation is achieved. In particular,when an automatic emergency braking function is provided in whichautomatic vehicle deceleration is triggered and/or performed forcollision avoidance and/or for alleviating the severity of thecollision, it is necessary that the detected objects be reliablydetectable and the distances and lateral dimensions of the objects beaccurately measurable. The remaining time to a possible collision with avehicle traveling ahead is accurately computable from the data of firstsurroundings sensing device 3, which provides longitudinalvalue-optimized measured values.

To evaluate the data of second surroundings sensing device 4, which maybe designed as a cost-effective, monocular video camera, for example,accurate values of the object dimensions may be obtained via opticalflow algorithms, which are known from the related art, and the knowndistance and velocity information provided by first surroundings sensingdevice 3. It is important both for the correct consideration of allavoidance options available to the driver when automatic emergencybraking is triggered and for automatically triggered and automaticallyperformed avoidance maneuvers of the vehicle equipped with the system ofthe present invention to know the lateral dimensions of objects in thevehicle's path which are relevant with regard to safety. First andsecond surroundings sensing devices 3, 4 should be selected in such away that second surroundings sensing device 4 is capable of deliveringaccurate values of the object data which first surroundings sensingdevice 3 is incapable of delivering or delivers inaccurately due tosystem limitations. Furthermore, first surroundings sensing device 3must be capable of accurately and reliably delivering object data whichsecond surroundings sensing device 4 is incapable of delivering ordelivers inaccurately due to system limitations. For example, providinga radar device as first surroundings sensing device 3 and acost-effective, monocular image detection system as second surroundingssensing device 4 is a preferred embodiment, because a radar system andmonocular video camera ideally complement one another regarding theaccuracy of object data deliverable under consideration of thelimitations of both systems.

It is also possible to evaluate the measured values of the longitudinalvalue-optimized surroundings sensing device in a first analyzer deviceand the measured values of the lateral dimension-optimized surroundingssensing device in a second analyzer device. The measured values of thesecond, i.e., lateral dimension-optimized surroundings sensing devicemay also be relayed to the analyzer device provided for longitudinalvalue-optimized analysis, where the longitudinal value-optimizedmeasured values may be verified using the additionally provided lateraldimension-optimized measured values and/or further object-specificinformation may be assigned to the detected objects. For example,another value regarding the lateral dimension of the object may beassigned to the objects detected by a radar system, which is impossibleor difficult to do using a pure radar system, or the signal processingof the radar system may be simplified by limiting the range of analysisto areas where objects have been detected by a video system.

Measured values of the longitudinal value-optimized surroundings sensingdevice may be additionally supplied to the analyzer device for thelateral dimension-optimized measured values. This makes verification ofthe lateral dimension-optimized measured values and provision of furtherinformation possible. Knowing the exact object distance, which is veryaccurately determinable using a radar system, a scaling factor of thelateral dimension-optimized image detection system may be properlydetermined or, knowing the direction and distance in which the radarsystem has detected an object, the image processing may be limited tocertain image areas of the video detection area to save processing time.

It is furthermore conceivable to implement both analyzer devices forlongitudinal value-optimized and lateral dimension-optimized measuredvalues in a single analyzer device, the lateral dimension-optimizedmeasured values being additionally supplied to the analysis algorithmfor processing the longitudinal value-optimized measured values, and thelongitudinal value-optimized measured values being supplied to thealgorithm for processing the lateral dimension-optimized measured valuesto verify the measured values or to obtain additional information, forexample, which is impossible to obtain due to system limitations.

On the basis of the determined objects and their movement-specificobject data, actuating signals for deceleration devices and accelerationdevices of the vehicle are formed in computing device 7 and are suppliedto an output circuit 8 via data exchange system 6. Output circuit 8outputs actuating signals to deceleration devices 9 of the vehicle whichprovide electronically controlled brake activation, for example, and arecapable of decelerating the vehicle as a function of the detectedobjects. An actuating signal is also supplied via output circuit 8 to anoutput-determining actuator element of a propulsion system 10, which maybe an electrically controlled throttle valve, for example, or anelectrically controlled fuel metering device for an injection system. Itis also conceivable for computing device 7 to deliver output signalswhich activate an electrically controlled steering system via dataexchange system 6 and output circuit 8 and are capable of steering thevehicle as a function of the detected objects which are relevant withregard to safety and are capable of performing an avoidance maneuver inthe event of an imminent collision with an object traveling ahead.

1. A device for triggering at least one of (1) at least one deceleration device and (2) at least one output-determining actuator element of a vehicle propulsion system, the device comprising: a first surroundings sensing device for providing longitudinal value-optimized measured values; a second surroundings sensing device for providing object lateral extension-optimized measured values; and an analyzer device for receiving output signals of the first and second surroundings sensing devices, and for using the measured values of both the first and second surroundings sensing devices for at least one of (a) object identification and (b) triggering of at least one of (1) the at least one deceleration device and (2) the at least one output-determining actuator element of the propulsion system; wherein one of: (a) the measured values of the second surroundings sensing device are used for at least one of verification and provision of additional information in analyzing the measured values of the first surroundings sensing device; and (b) the measured values of the first surroundings sensing device are used for at least one of verification and provision of additional information in analyzing the measured values of the second surroundings sensing device.
 2. The device according to claim 1, wherein the device is for at least one of an automatic longitudinal vehicle regulation and an object identification.
 3. The device according to claim 2, wherein the longitudinal vehicle regulation provides for automatic vehicle deceleration to be at least one of triggered and performed to at least one of: avoid a collision and alleviate a severity of a collision.
 4. The device according to claim 1, wherein the first surroundings sensing device is a radar transceiver device.
 5. The device according to claim 1, wherein the first surroundings sensing device is a lidar transceiver device.
 6. The device according to claim 1, wherein the second surroundings sensing device is an image detection system.
 7. The device according to claim 6, wherein the image detection system includes a monocular video camera.
 8. The device according to claim 6, wherein the image detection system includes a stereo video camera.
 9. A method for triggering at least one of(1) at least one deceleration device and (2) at least one output-determining actuator element of a vehicle propulsion system, the method comprising: receiving in an analyzer device output signals of a first surroundings sensing device and a second surroundings sensing device, the first surroundings sensing device providing longitudinal value-optimized measured values, and the second surroundings sensing device providing object lateral extension-optimized measured values; using the measured values of both the first and second surroundings sensing devices for object identification, wherein one of: (a) the measured values of the second surroundings sensing device are used for at least one of verification and provision of additional information in analyzing the measured values of the first surroundings sensing device; and (b) the measured values of the first surroundings sensing device are used for at least one of verification and provision of additional information in analyzing the measured values of the second surroundings sensing device; and activating at least one of (1) at least one deceleration device and (2) at least one output-determining actuator element of the propulsion system as a function of a determined surroundings situation.
 10. The method according to claim 9, wherein the method is for automatic longitudinal vehicle regulation.
 11. The method according to claim 10, wherein the longitudinal vehicle regulation provides for automatic vehicle deceleration to be at least one of triggered and performed to at least one of: avoid a collision and alleviate a severity of a collision. 